Originally, authorities said the Bensalem, Pa., native also violently sexually assaulted five other girls over a five-month time period when he was under the age of 18. All of the victims were between the ages of 14 and 16, officials said.

After media coverage of Benson's arrest, another woman came forward and said he assaulted her in 2011 when she was just 17. Since the alleged assault occurred when Benson was also underage additional charges were filed in juvenile court, according to police.

Teen Rape Suspect Under Investigation for Years

Benson moved to the area from Utah about three years ago, shortly before the alleged assaults began, officials said.

Benson, who cursed at reporters on his way into court following his arrest, met some of his victims on a dating website and others through friends, authorities confirm. They say the teen would befriend the girls and make them trust him before violently forcing himself on them.

"Once he befriended them and gained trust in them where they agreed to have a very short-term relationship with him. Once he began engaging in sexual contact it immediately turned violent," Bensalem Police Sgt. Andrew Aninsman said.

The most recent victims say they were forced to perform sex acts in the basement of a townhome along Arrowood Drive in Bensalem, officials said.

"We do believe there are many other victims out there and if you see this, and your gut is wrenching as to what happened to you, pick up the phone and call Bensalem Police and we will make sure that we do everything in our power to make sure you get justice," said Aninsman.